This proposal addresses two National Occupational Research Agenda priority areas: occupational health services research and low back pain. Back pain among workers is an enormous medical, social, and economic burden in the United States. Back disorders account for 27% of all disabling occupational injuries in the United States and the average direct cost of a low back injury claim is more than twice that of other occupational injury claims combined. The primary goal of the study is to examine community differences in the rate and types of spinal surgery performed on injured workers using small area analysis. Small area analysis is a commonly employed method in health services research but there have been limited applications of this technique in occupational health research. Oregon, as well as a number of neighboring Western states, has been identified as having elevated rates of spine surgery compared to the rest of the nation and significant local variation exists among communities based on prior analyses of Medicare claims data. We plan to evaluate whether a similar pattern of local variation exists for workers' compensation claims and to evaluate factors contributing to observed variations including physician specialty, physician supply, source of payment, and the effect of managed care. This project will pilot the use of an existing comprehensive state database of workers' compensation medical payments that provides rich opportunities for health services and outcomes research in occupational health. The methods described in this application can be applied to other geographic units or other diagnoses and thereby serves as a model for analyzing the individual, community and provider variables that influence the treatment of work-related injuries and illnesses.